RU2486011C2 - Method of locking shredder roll discs - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to grinding of various materials with the help of Shredder rolls. Locking of Shredder roll discs consists in clutching discs on the shaft between thrust elements transmitting the torque. Discs and thrust elements are furnished with holes arranged equidistant from the center. Rods with threaded ends are fitted in said holes. Discs are locked between fixed thrust element fitted on shaft collar and thrust element that displaces axially. Nuts being tightened act on the latter. If required, disc teeth helix may be changed and replaced directly at production line.

EFFECT: one rigger can strain the stack of discs.

1 dwg

Description

The invention relates to equipment for processing various materials, such as wood waste, used tires, solid waste, sheet metal, steel shavings, and can be used in various industries and utilities.

The processing of various materials and their wastes that are in a chaotic state and to one degree or another contaminated with mineral and metal impurities became possible only with the advent of low-speed roll crushers, the so-called shredders. The main distinguishing feature of shredders is that the working bodies of the roll are composed of disks and intermediate rings (there are designs where the disk is integral with the ring, which can be located either symmetrically or asymmetrically), depending on the purpose, i.e. . type of material, the discs may have one or more teeth on the peripheral part. The last of one roll go into the gaps formed by the rings of another roll, creating a working area that draws and grinds the material regardless of its position and condition.

Due to the fact that the processed material, as a rule, is in a chaotic state and has a low bulk density and low density, the length of the working bodies of the shredders should be quite large, respectively, and a large number of disks. From here the most difficult task arises when creating a highly efficient shredder - how to fix the disks on the shafts so that they transmit the maximum torque, how to mount and replace them in case of failure.

There are various methods of fixing discs on shafts. For example, disks on a shaft according to the Swedish patent No. 436714, cl. B27L 11/00 1985 are fixed by heating the shaft to a certain temperature of the assembled roll and installing a snap ring. After cooling, a stressed state of the shaft is created, which should ensure the transmission of torque of the disks on the installed helical line due to friction forces.

But as the operating experience of the crushers according to this patent shows, a helix failure occurs, which significantly reduces the efficiency of the work. To install the optimal helix or to replace any disk, it is necessary, as the patentee recommends, to deliver the roll to the manufacturer or have a spare roll, which requires significant financial costs.

This disadvantage is deprived of the Wikmax crusher, in which the disks are fixed by tightening the threaded shaft element with the drive of the second roller while holding the shaft of the first brake (Patent No. 2023505, V02C 4/02, 4/30, 1991). The operation of the crusher showed its high efficiency, but the complexity of the design served as a serious obstacle to widespread adoption.

Known methods for rigidly fixing discs to a shaft using classic dowels or profile shafts made in the form of a hexagon (see patents: Japan 62-14341, B02C 18/06, 1987; European patent 0110665, B02C 4/30, 1984, American patent No. 4046324, B02C 13/06, B02C 23/36, 1997). All these designs, in addition to technical difficulties in manufacturing, have a serious design flaw, namely, that to obtain a helical line, each disk has its own design, moreover, it is impossible to ensure the reliability of such devices at maximum loads, because the entire load falls on one disk, and the thickness of the disks is very limited due to their design features.

The closest in design is the "Device for grinding" (Patent No. 1745549, B27Z 11/00, 1988), in which the torque is transmitted to the disks through the rods installed in the holes of the disks and blind holes of the stop elements, which are affected by tightening one brake, and on the second drive roll.

This device is difficult in design, and to bring the rolls into working condition, it is necessary to completely assemble the crusher, since the tightening is done by braking one thrust element and acting on the other drive. Moreover, for disassembling the roll, it is required to loosen the tightening by the drive and only then disassemble the roll and proceed with disassembly.

The purpose of the invention is to simplify the design.

The goal is achieved as follows. The disks are fixed on the roll shaft due to the frictional forces created during the stress state of the group of rods that connect the thrust elements fixed to the shaft and the disks, and at the ends of the rods there are threaded sections onto which the nuts are tightened at a certain moment.

The invention is illustrated in the drawing, which shows a section along the axial line of the roll option.

The roll consists of a shaft 1, which has sections 2 and 3 for fixing the thrust elements 5 and 6, which can be structurally made in the form of a key, splined or profile connection (see. "Machine parts". A.T. Baturin and others. Edition . "Engineering" M., 1970, p.143). The shaft 1 also has a journal for bearings and a drive end (not shown in the drawing), as well as a shoulder 4 for fixing in the longitudinal direction of the stop element 5 and the entire package of disks. There is a shaft option with a groove and a standard retaining ring. Disks 7 and intermediate rings 8 are mounted on the smooth part of shaft 1. Thrust elements 5, 6, as well as disks 7 and rings 8 are provided with holes equally spaced from the center, into which rods 9 are inserted, having threaded sections at the ends (in essence and hereinafter - studs) on which the nuts 10 are screwed.

Assembly roll is as follows. A stop element 5 is mounted on the shaft 1 from the drive end to section 2, the latter having a groove that extends onto the shoulder 4 of the shaft 1, the holes are threaded where the studs 9 are screwed, and then the discs 7 are strung onto the smooth part of the shaft 1 and the stud 9 and intermediate rings 8, and depending on the desired configuration of the so-called helical line of the teeth of the disks, each subsequent disk is oriented relative to the previous one and is installed, sequentially moving to the stop element 5. After installing all the disk and in the rings on the shaft portion 3 and the ends of the pins 9 set the abutment member 6 and the nut 10 are twisted.

Upon reaching the limit moments of all nuts, the latter are firmly fixed. The drawing shows a variant of locking nuts 10 in pairs using retaining folding strips.

In addition to the high reliability of such a roll design, it works as a composite beam, because when the connection is sufficiently tightened, the bending stiffness of such a beam is equal to the stiffness of a continuous beam (see I. A. Birger. “Calculation of threaded joints.” Ed. Second, Oborongiz, M., 1959, pp. 44-51), therefore, bending not only the shaft works, but also the pack of discs and rings on the outer diameter of the latter.

Particular attention should be paid to this, as A fairly large experience in operating shredders shows that in the processing of unfinished tires or metal housings of household appliances there are great spacer efforts. They lead to bending of the shafts, which creates extreme loads on the bearings, and put them out of action, moreover, at the same time, the junction of the disks and the intermediate rings occurs periodically, which ultimately leads to devastating consequences.

The design of the roll according to the claimed method has advantages, because provides:

- control of the degree of tightening of the nuts during the assembly of the roll using well-known control methods (lengthening the rods, turning the nut, torque on the torque wrench);

- dismantling and mounting of disks with a change in their relative position under operating conditions, corresponding to a material with different dimensional and strength characteristics from previously processed ones;

- the reliability of the disks during operation of the crusher with maximum loads, a significant reduction in the arrow of the deflection of the rolls, because the roll works like a continuous beam;

- when tightening the nuts by the installer using a normal wrench, a friction force is created that ensures the roll is operable at maximum loads, because the "broom system" is applied, i.e. a large number of thin rods compared to the shaft, which gives a total significant effort.

Claims (1)

The method of fixing the disks of the shredder roll, which consists in tightening the disks on the shaft between the stop elements that transmit torque, both of which are made with holes equidistant from the center, while the holes have threaded rods at the ends, characterized in that the disks are fixed between the fixed stop element, which is mounted on the shoulder of the shaft, and the axial element, which is movable in the axial direction, the nuts acting on the latter when tightening them.

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